help, with properly spined arrow..
 

I shoot a mathews Q2 with a 29 inch draw length. It's set at 70#.can someone tell me how many total grains i need in my arrow set-up??

RE: help, with properly spined arrow..
 

The total weight of the arrow has nothing to do with the spine. There are carbon arrow that will spine correctly for your set up that weigh as little a 5. something grains per inch up to about 15 grains per inch.

A good weight arrow for a set up like yours would be somewhere around 450 grains to 500 grains. This will give you plenty of penetrating power while still allowing a fairly flat trajectory. An arrow of this weight will also keep your bow fairly quiet for hunting as well and will be much more pleasant to shoot.